On 08.06.21 21:00, Jason Gunthorpe wrote:
Eg I can do open() on a file and I get to keep that FD. I get to keep that FD even if someone later does chmod() on that file so I can't open it again. There are lots of examples where a one time access control check provides continuing access to a resource. I feel the ongoing proof is the rarity in Unix.. 'revoke' is an uncommon concept in Unix..
Yes, it's even possible that somebody w/ privileges opens an fd and hands it over to somebody unprivileged (eg. via unix socket). This is a very basic unix concept. If some (already opened) fd now suddenly behaves differently based on the current caller, that would be a break with traditional unix semantics. --mtx -- --- Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren GPG/PGP-Schlüssel zu. --- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering info@xxxxxxxxx -- +49-151-27565287
